Study Guides (390,000)
CA (150,000)
York (10,000)
NURS (20)
Study Guide

[NURS 2533] - Midterm Exam Guide - Comprehensive Notes for the exam (26 pages long!)


Department
Nursing
Course Code
NURS 2533
Professor
Irfan Ahmed
Study Guide
Midterm

This preview shows pages 1-3. to view the full 26 pages of the document.
York
NURS 2533
MIDTERM EXAM
STUDY GUIDE

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

NURS 2533 Chapter 14: Mechanisms of Infectious Disease
General Concepts of Infectious Diseases
Under extraordinary circumstances, the invasion of the human body by microorganisms
can produce harmful and potentially lethal consequences called infectious diseases.
Terminology
Host: any organism capable of supporting the nutritional and physical growth requirements of
another organism.
Ex. humans supporting the growth of microorganisms.
Infection: the presence and multiplication within another living organism, with subsequent
injury to the host
Colonization: the act of establishing a presence
a step required in the multifaceted process of infection.
Occasionally, infection and colonization are used interchangeably.
Normal micro flora: bacteria that normally and harmlessly inhabit the internal and external
exposed surfaces of the human body
not all interactions between microorganisms and humans are detrimental, most of
these interactions are beneficial.
Commensalism: an interaction where the colonizing bacteria acquire nutritional support from
the host, but the host is not adversely affected by the relationship.
Commensal flora: a term sometimes used to refer to colonizing microorganisms
Mutualism: an interaction in which the microorganism and the host both derive benefits from
the interaction.
For example, certain inhabit- ants of the human intestinal tract extract nutrients from
the host and secrete essential vitamin by-products of metabolism (e.g., vitamin K) that
are absorbed and used by the host.
Parasitic relationship: relationship in which only the infecting organism benefits from the
relationship and the host either gains nothing from the relationship or sustains injury from the
interaction.
Infectious disease: occurs if the host sustains injury in a parasitic relationship.
The severity of an infectious disease can range from mild to life-threatening depending
on many variables including:
1. the health of the host at the time of infection
2. the virulence of the microorganism.
Virulence: the disease-producing potential of the microorganism.
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Pathogens: A select group of microorganisms that are so virulent that they are rarely found in
the absence of disease.
there are few human pathogens in the microbial world.
Saprophytes: free-living organisms obtaining their growth from dead or decaying organic
material in the environment.
Most microorganisms
harmless
Opportunistic pathogens: microorganisms capable of producing an infectious disease when the
health and immunity of the host have been severely weakened by illness, malnutrition, or
medical therapy.
Includes all microorganisms, even saprophytes and members of the normal flora.
Agents of Infectious Disease
Agents of infectious disease include:
1. Prions,
2. Viruses,
3. Bacteria,
4. Rickettsiaceae
5. Chlamydiaceae,
6. Fungi,
7. Parasites
1. Prions
Can a protein alone cause a transmissible infectious disease?
Prions: protein particles that lack RNA or DNA.
A number of prion-associated diseases have been identified, including: Creutzfeldt Jakob
disease in humans, scrapie in sheep, and bovine spongiform encephalopathy (BSE or
mad cow disease) in cattle.
Transmissible neurodegenerative diseases: The collection of various prion-associated diseases
—i
TA BLE 1 4 - 1 Co m paris on o f Ch aracte ristics o f Hum an Micro bial Pathoge ns
Org a n is m De n e d N u c le u s Gen o m ic M a t e r ia l S iz e *
In t r a c e llu la r o r
Ext r a c e llu la r M o t ilit y
Pr io n s No Un kn ow n 55 kDa E
Viru s e s No DNA or RNA 0.02–0.3 I
Ba cte r ia No DNA 0.5–15 I/E ±
Myc o pla s m a s No DNA 0.2–0.3 E
S p iro ch e te s No DNA 6–15 E +
Ricke tts ia c ea e No DNA 0 .2–2 I
Chla m y d ia ce a e N o DNA 0.3–1 I
Ye a s ts Ye s DNA 2–60 I/E
Mo ld s Ye s DNA 2–15 E
(hyp h a l w id th )
Pr o to zo a n s Ye s DNA 1 –60 I/E +
He lm in th s Yes DNA 2 m m to >1 m E +
*Micro m ete rs un le s s ind ica ted .
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version